The effectiveness of massaging devices provided with mobile bodies has led to the design and production of various types of electrically-driven devices. However, these devices may not be used in the presence of water, owing to the risk of electric shock, so that it is not possible to use them for various types of hydrotherapy treatments combined with massaging.
Alternatively, it has been attempted to use, instead of an electric motor, various vibrating devices energized by a flow of water, but the effects of a vibratory massaging are very different from those of rotary mobile bodies riding on the patient's body.
Thus, there does not appear to have been available, from prior art, a simple and practical device adapted for being handled by a massager or by the patient himself, provided with ball-shaped rotary bodies which may be firmly applied on the patient's body while having sufficient driving force for sustaining their rotary motion and simultaneously releasing water with sufficient kinetic energy for producing an effective hydrotherapeutic action.
Rotary devices energized by water pressure have been described for driving circular brushes intended for washing automobiles. One such device, described in French Pat. No. 1,568,301 comprises a small turbine driven by the flow of water from a public distribution network. However, while such a device may be appropriate for driving a circular brush gliding over the smooth surface of a car body which is abundantly irrigated with water, this type of device is completely inappropriate for supplying the driving power requested for driving mobile bodies while these are firmly applied against a patient's limbs. Also, water flowing out of such a brush-driving device flows all around the brush, so that its residual kinetic energy is completely dissipated. It will be clearly apparent that such a device could not be used as a massaging device in hydrotherapeutic treatments, since the exhaust water would simply trickle away from the body part which is being massaged, whenever the device is turned sideways or upwards.